1. Field of the Invention
The present invention relates to a boat propulsion unit and a boat having the boat propulsion unit in which shifting between forward, neutral, and reverse is electrically performed by remote control.
2. Description of the Related Art
One conventional boat of this type is disclosed in JP-A-2005-297785.
It is described in JP-A-2005-297785 that a shift device includes a remote control operation device having a remote control shift lever for remotely shifting between forward, neutral, and reverse; a boat propulsion unit having a shifting device for shifting between forward, neutral, and reverse, and a shift actuator for driving the shifting device; and a controller for controlling the operation of the shift actuator based on the displacement of the remote control shift lever when the remote control shift lever is operated within a prescribed shift range from a neutral position; wherein the controller controls the operation amount of the actuator with respect to a unit displacement of the remote control shift lever such that it is different in different sections of the shift range.
However, in such a conventional device, when the remote control shift lever is quickly rotated to reverse from an advancing mode to make a shift-in in the opposite direction, a shift-in to reverse is done before the engine rotational speed and the boat speed are sufficiently reduced. Then, a shock at that time may be exerted on the gears in meshing engagement with each other and the boat may have an abrupt movement.
That is, when the remote control shift lever is quickly rotated to reverse from a forward mode to make a shift-in in the opposite direction, since a force urges the propeller to rotate in the opposite direction while the propeller is still rotating in the forward direction and an inertia force in that direction is generated, a large force is generated between the gears on the propeller side and the gears on the engine side. Then, a shock at that time may be exerted on the gears, and the boat may have an abrupt movement.